The present invention relates to an operation wire connecting part in an endoscopic treating instrument.
Generally, the endoscopic treating instrument is so constructed that an operation wire is disposed in a sheath so as to move back and forth in an axial direction, and an operating section for manipulating the operation wire to move it back and forth in an axial direction is connected to a base end of the sheath. In not a few endoscopic treating instrument, the sheath and the operation wire which are, so to speak, consumable items are detachably constructed with respect to the operating section.
The operation wire connecting part in most of the endoscopic treating interments is so constructed that a connecting rod attached to a base end portion of the operation wire which has been drawn out from the base end of the sheath is passed through an engaging groove formed in an operating member, and the engaging groove is moved in a direction perpendicular to an axis of the connecting rod allowing a small width portion of the engaging groove to be engaged with a small diameter portion formed in the connecting rod, whereby the connecting rod is adapted to move integrally with the operating member.
Generally, there have been prepared a plurality of endoscopic treating instruments, for the same type of treatment, having respective different diameters of the sheathes and the operation wires so as to match with a selected endoscope to be used. That is, a suitable one of endoscopic treating instruments is selected depending on the selected one of endoscopes having respective different diameters of treating instrument insertion channels, so that the sheath and operation wire in the selected endoscopic treating instrument match in diameter with the treating instrument insertion channel of the selected endoscope.
As the sheathes and the operation wires are different in diameter, outer diameters of the small diameter portions of the connecting rods respectively fixed to the base ends of the operation wires are different, and the widths of the engaging grooves in the respective operating sections to be engaged with the small diameter portions are also different. For this reason, it is necessary to separately prepare various types of the operating sections having respective different widths of the engaging grooves to match with the diameters of the sheathes and the operation wires. This requires complicated and cumbersome handling.
In view of the above, it is an object of the invention to provide an operation wire connecting part in an endoscopic treating instrument which can be commonly used for and connectable to sheathes and the operation wires having different diameters, thereby providing flexibility.
According to the invention, because width of a small width portion of the engaging groove is made different according to positions, so that plural types of the connecting rods having the small diameter portions which are different in diameter can be selectively engaged with the engaging groove. Therefore, the treating instruments in which the diameters of the sheathes and the operation wires are different can be connected to the same operating section for use, and the general versatility or flexibility of the operating section can be greatly enhanced.
An operation wire connecting part in an endoscopic treating instrument according to a preferred embodiment the invention is so constructed that a base end of an operation wire passed through a sheath axially movably is drawn out from a base end of the sheath, a connecting rod on the base end of the operation wire is passed through an engaging groove provided in an operating member for manipulating the operation wire to move it back and forth in an axial direction, and the engaging groove is moved in a direction perpendicular to an axis of the connecting rod allowing a small width portion of the engaging groove to be engaged with a small diameter portion formed in the connecting rod, whereby the connecting rod is adapted to move integrally with the operating member. In the connecting part of the preferred embodiment, the small width portion of the engaging groove is made different in width according to positions, thereby enabling plural types of the connecting rods having different diameters at their small diameter portions to be engaged with the engaging groove.
The width of the small width portion of the engaging groove may vary as a plurality of steps in a stepwise manner, or may gradually vary.
Preferably, the engaging groove may be biased in a direction where the connecting rod is positively engaged with the small width portion so as to prevent the disengagement of the connecting rod from the engaging groove.
The present disclosure relates to the subject matter contained in Japanese patent application No. Hei. 11-221131 (filed on Aug. 4, 1999), which is expressly incorporated herein by reference in its entirety.